Add django-cacheback to cache map JSON blobs for faster map render

[Andrew-Dickinson]

This PR adds django-cacheback which allows the content of the map endpoints to be loaded asynchronously into redis for caching purposes. Then at request time, Django just pulls the JSON blob from Redis and serves it, saving expensive database calls

[Andrew-Dickinson]

Hmm I may abandon this effort. Even with the best case performance of the backend (cache hit, zero network overhead due to local hosting), we perform significantly worse than the existing map. I think looking into some kind of batch pre-computation solution similar to the existing map is probably the way to go...

https://github.com/user-attachments/assets/0ec75925-b5e8-48e7-bcf3-f6b67539883b

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 99.20000% with 1 line in your changes missing coverage. Please review.

Project coverage is 94.79%. Comparing base (0e1b434) to head (85b31dd).

Files	Patch %	Lines
src/meshapi/util/map_data.py	98.70%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #443 +/- ## ========================================== + Coverage 94.76% 94.79% +0.03% ========================================== Files 101 102 +1 Lines 5025 5076 +51 ========================================== + Hits 4762 4812 +50 - Misses 263 264 +1 ```

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[Andrew-Dickinson]

Confirmed with Willard on a call tonight, we're gonna kill this one and do this caching by pre-baking the map data in the npm build inside the docker container which serves the map, similar to the behavior of the original map